The ventral and dorsal striatum are part of a neural network that is strongly implicated in the rewarding, reinforcing, and learning processes that occur with administration of addictive substances. The coordinated activation of dopamine and glutamate receptors within this system is thought to be a key mechanism by which these drugs (e.g., alcohol) produce their effects. The aim of this proposal is to monitor extracellular dopamine and glutamate in the nucleus accumbens and dorsal striatum concurrently during associative learning and operant self-administration of alcohol, with dual probe microdialysis. In this procedure, rats will be trained to respond operantly using ethanol + sucrose, sucrose, or water reinforcement. The microdialysis test will occur very early in training, after the animals initially acquire the capacity for operant self-administration. These experiments will distinguish between appetitive and consummatory behaviors and the accompanying neuronal responses. The overall hypothesis is that extracellular dopamine and glutamate are elevated during operant learning and ethanol self-administration.